Electronic lockouts and surgical instrument including same

ABSTRACT

A surgical cutting and stapling instrument is disclosed. The instrument includes an end effector and a handle. The end effector includes a channel, an anvil pivotally attached to the channel, a moveable cutting instrument for cutting an object positioned between the anvil and the channel, and a staple cartridge configured for removable receipt by the channel. The staple cartridge includes a sled that is engaged by the cutting instrument during a cutting stoke. The handle includes a motor for actuating the cutting instrument via a main drive shaft assembly. The instrument further includes a first interlock circuit for enabling initiation of motor operation based upon a position of the staple cartridge.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is related to the following concurrently-filedU.S. patent applications, which are incorporated herein by reference:

(1) MOTOR-DRIVEN SURGICAL CUTTING AND FASTENING INSTRUMENT WITH USERFEEDBACK SYSTEM; Inventors: Frederick E. Shelton, IV, John Ouwerkerk,and Jerome R. Morgan (U.S. application Ser. No. 11/343,498);

(2) MOTOR-DRIVEN SURGICAL CUTTING AND FASTENING INSTRUMENT WITH LOADINGFORCE FEEDBACK; Inventors: Frederick E. Shelton, IV, John N. Ouwerkerk,Jerome R. Morgan, and Jeffrey S. Swayze (U.S. application Ser. No.11/343,573);

(3) MOTOR-DRIVEN SURGICAL CUTTING AND FASTENING INSTRUMENT WITH TACTILEPOSITION FEEDBACK; Inventors: Frederick E. Shelton, IV, John N.Ouwerkerk, Jerome R. Morgan, and Jeffrey S. Swayze (U.S. applicationSer. No. 11/344,035);

(4) MOTOR-DRIVEN SURGICAL CUTTING AND FASTENING INSTRUMENT WITH ADAPTIVEUSER FEEDBACK; Inventors: Frederick E. Shelton, IV, John N. Ouwerkerk,and Jerome R. Morgan (U.S. application Ser. No. 11/343,447);

(5) MOTOR-DRIVEN SURGICAL CUTTING AND FASTENING INSTRUMENT WITHARTICULATABLE END EFFECTOR; Inventors: Frederick E. Shelton, IV andChristoph L. Gillum (U.S. application Ser. No. 11/343,562);

(6) MOTOR-DRIVEN SURGICAL CUTTING AND FASTENING INSTRUMENT WITHMECHANICAL CLOSURE SYSTEM; Inventors: Frederick E. Shelton, IV andChristoph L. Gillum (U.S. application Ser. No. 11/344,024);

(7) SURGICAL CUTTING AND FASTENING INSTRUMENT WITH CLOSURE TRIGGERLOCKING MECHANISM; Inventors: Frederick E. Shelton, IV and Kevin R. Doll(U.S. application Ser. No. 11/343,321);

(8) GEARING SELECTOR FOR A POWERED SURGICAL CUTTING AND FASTENINGSTAPLING INSTRUMENT; Inventors: Frederick E. Shelton, IV, Jeffrey S.Swayze, and Eugene L. Timperman (U.S. application Ser. No. 11/343,563);

(9) SURGICAL INSTRUMENT HAVING RECORDING CAPABILITIES; Inventors:Frederick E. Shelton, IV, John N. Ouwerkerk, and Eugene L. Timperman(U.S. application Ser. No. 11/343,803);

(10) SURGICAL INSTRUMENT HAVING A REMOVABLE BATTERY; Inventors:Frederick E. Shelton, IV, Kevin R. Doll, Jeffrey S. Swayze, and EugeneTimperman (U.S. application Ser. No. 11/344,020);

(11) ENDOSCOPIC SURGICAL INSTRUMENT WITH A HANDLE THAT CAN ARTICULATEWITH RESPECT TO THE SHAFT; Inventors: Frederick E. Shelton, IV, JeffreyS. Swayze, Mark S. Ortiz, and Leslie M. Fugikawa (U.S. application Ser.No. 11/343,547);

(12) ELECTRO-MECHANICAL SURGICAL CUTTING AND FASTENING INSTRUMENT HAVINGA ROTARY FIRING AND CLOSURE SYSTEM WITH PARALLEL CLOSURE AND ANVILALIGNMENT COMPONENTS; Inventors: Frederick E. Shelton, IV, Stephen J.Balek, and Eugene L. Timperman (U.S. application Ser. No. 11/344,021);

(13) DISPOSABLE STAPLE CARTRIDGE HAVING AN ANVIL WITH TISSUE LOCATOR FORUSE WITH A SURGICAL CUTTING AND FASTENING INSTRUMENT AND MODULAR ENDEFFECTOR SYSTEM THEREFOR; Inventors: Frederick E. Shelton, IV, MichaelS. Cropper, Joshua M. Broehl, Ryan S. Crisp, Jamison J. Float, andEugene L. Timperman (U.S. application Ser. No. 11/343,546); and

(14) SURGICAL INSTRUMENT HAVING A FEEDBACK SYSTEM; Inventors: FrederickE. Shelton, IV, Jerome R. Morgan, Kevin R. Doll, Jeffrey S. Swayze, andEugene Timperman (U.S. application Ser. No. 11/343,545).

FIELD OF THE INVENTION

The disclosed invention relates generally and in various embodiments tosurgical stapling and cutting instruments structured and configured forapplying lines of staples from a reusable staple cartridge into tissuewhile cutting the tissue between the applied staple lines. Moreparticularly the disclosed invention relates to electronic interlocksfor use in motorized surgical stapling and cutting instruments thatprevent cutting of the tissue when the staple cartridge is notinstalled, is improperly installed, or is spent, or when the surgicalstapling and cutting instrument is not otherwise in a condition toperform a stapling and cutting operation in a safe and/or optimalmanner. The disclosed invention further relates to electronic interlocksfor disabling use of certain instrument features while a stapling andcutting operation is in progress.

BACKGROUND

Endoscopic surgical instruments are often preferred over traditionalopen surgical devices since a smaller incision tends to reduce thepost-operative recovery time and complications. Consequently,significant development has gone into a range of endoscopic surgicalinstruments that are suitable for precise placement of a distal endeffector at a desired surgical site through a cannula of a trocar. Thesedistal end effectors engage the tissue in a number of ways to achieve adiagnostic or therapeutic effect (e.g., endocutter, grasper, cutter,staplers, clip applier, access device, drug/gene therapy deliverydevice, and energy device using ultrasound, RF, laser, etc.).

Known surgical staplers include an end effector that simultaneouslymakes a longitudinal incision in tissue and applies lines of staples onopposing sides of the incision. The end effector includes a pair ofcooperating jaw members that, if the instrument is intended forendoscopic or laparoscopic applications, are capable of passing througha cannula passageway. One of the jaw members receives a staple cartridgehaving at least two laterally spaced rows of staples. The other jawmember defines an anvil having staple-forming pockets aligned with therows of staples in the cartridge. The instrument includes a plurality ofreciprocating wedges which, when driven distally, pass through openingsin the staple cartridge and engage drivers supporting the staples toeffect the firing of the staples toward the anvil.

Advantageously, the design of the end effector may be such that it canbe reused with the surgical stapler. For instance, one patient may needa series of severing and stapling operations. Replacing an entire endeffector for each operation tends to be economically inefficient,especially if the end effector is built for strength and reliabilityover repeated operations. To that end, the staple cartridge is typicallyconfigured to be disposable and is fitted into the end effector prior toeach operation of the surgical stapler.

An example of a surgical stapler suitable for endoscopic applications isdescribed in U.S. Pat. No. 5,465,895, entitled “SURGICAL STAPLERINSTRUMENT” to Knodel et al., which discloses an endocutter withdistinct closing and firing actions. Thereby, a clinician is able toclose the jaw members upon tissue to position the tissue prior tofiring. Once the clinician has determined that the jaw members areproperly gripping tissue, the clinician can then fire the surgicalstapler with either a single firing stroke or multiple firing strokes,depending on the device. Firing the surgical stapler causes severing andstapling of the tissue. The simultaneous severing and stapling avoidscomplications that may arise when performing such actions sequentiallywith different surgical tools that respectively only sever and staple.

One specific advantage of being able to close upon tissue before firingis that the clinician is able to verify via an endoscope that thedesired location for the cut has been achieved, including a sufficientamount of tissue has been captured between opposing jaws. Otherwise,opposing jaws may be drawn too close together, especially pinching attheir distal ends, and thus not effectively forming closed staples inthe severed tissue. At the other extreme, an excessive amount of clampedtissue may cause binding and an incomplete firing.

Because the actuating force (i.e., the “force-to-fire”, or FTF)necessary to close the jaws arid simultaneously perform the cutting andstapling operation may be considerable, a manually-powered cutting andstapling instrument such as that described above may not be utilizableby otherwise qualified users who are unable to generate the requiredFTF. Accordingly, powered cutting and stapling instruments have beendeveloped for decreasing the force-to-fire (FTF). Such instrumentstypically incorporate motors or other actuating mechanisms suitable forsupplementing or replacing user-generated force for performing thecutting and stapling operation.

Although powered instruments provide numerous advantages, it isdesirable to prevent inadvertent firing of the instrument under certainconditions. For example, firing the instrument without having a staplecartridge installed, or firing the instrument having an installed butspent staple cartridge, may result in cutting of tissue withoutsimultaneous stapling to minimize bleeding. Additionally, firing of theinstrument without proper closure of the jaw members may result in anunacceptable cutting and stapling operation and/or cause mechanicaldamage to the instrument. Similar consequences may result if the jawmembers are inadvertently opened while a cutting and stapling operationis in progress. It is particularly desirable that interlock features forpreventing such inadvertent firing and jaw manipulation be accomplishedin a reliable way that is not subject to an intervening malfunction.Moreover, for ease of manufacturing and assembly, it is furtherdesirable that the interlock features be accomplished with a minimumnumber of components.

Consequently, a significant need exists for electronic interlockfeatures for use in powered cutting and stapling instruments thatprevent inadvertent firing (i.e., cutting and stapling) and jawmanipulation during conditions such as those described above.

SUMMARY

The present invention discloses a surgical cutting and staplinginstrument according to various embodiments. The instrument includes anend effector and a handle. The end effector includes a channel, an anvilpivotally attached to the channel, a moveable cutting instrument forcutting an object positioned between the anvil and the channel, and astaple cartridge configured for removable receipt by the channel. Thestaple cartridge includes a sled that is engaged by the cuttinginstrument during a cutting stroke. The handle includes a motor foractuating the cutting instrument via a main drive shaft assembly. Theinstrument further includes a first interlock circuit for enablinginitiation of motor operation based upon a position of the staplecartridge. In certain embodiments, the instrument may further include asecond interlock for preventing pivotal movement of the anvil relativeto the channel during movement of the cutting instrument. The secondinterlock circuit may include an electromechanical actuator configuredto prevent opening of the anvil relative to the channel during movementof the cutting instrument.

DRAWINGS

Various embodiments of the present invention are described herein by wayof example in conjunction with the following figures, wherein

FIGS. 1 and 2 are perspective views of a surgical cutting and fasteninginstrument according to various embodiments of the present invention;

FIGS. 3-5 are exploded views of an end effector and shaft of theinstrument according to various embodiments of the present invention;

FIG. 6 is a side view of the end effector according to variousembodiments of the present invention;

FIG. 7 is an exploded view of the handle of the instrument according tovarious embodiments of the present invention;

FIGS. 8 and 9 are partial perspective views of the handle according tovarious embodiments of the present invention;

FIG. 10 is a side view of the handle according to various embodiments ofthe present invention;

FIG. 11 is a schematic diagram of a circuit used in the instrumentaccording to various embodiments of the present invention;

FIGS. 12-13 are side views of the handle according to other embodimentsof the present invention;

FIGS. 14-22 illustrate different mechanisms for locking the closuretrigger according to various embodiments of the present invention;

FIGS. 23A-B show a universal joint (“u-joint”) that may be employed atthe articulation point of the instrument according to variousembodiments of the present invention;

FIGS. 24A-B shows a torsion cable that may be employed at thearticulation point of the instrument according to various embodiments ofthe present invention;

FIGS. 25-31 illustrate a surgical cutting and fastening instrument withpower assist according to another embodiment of the present invention;

FIGS. 32-36 illustrate a surgical cutting and fastening instrument withpower assist according to yet another embodiment of the presentinvention;

FIGS. 37-40 illustrate a surgical cutting and fastening instrument withtactile feedback according to embodiments of the present invention;

FIGS. 41-42 illustrate a proportional sensor that may be used accordingto various embodiments of the present invention; and

FIGS. 43A-44C illustrate mounting arrangements and configurations of thelockout sensor switches of the interlock circuit according to variousembodiments of the present invention.

DETAILED DESCRIPTION

FIGS. 1 and 2 depict a surgical cutting and fastening instrument 10according to various embodiments of the present invention. Theillustrated embodiment is an endoscopic instrument and, in general, theembodiments of the instrument 10 described herein are endoscopicsurgical cutting and fastening instruments. It should be noted, however,that according to other embodiments of the present invention, theinstrument may be a non-endoscopic surgical cutting and fasteninginstrument, such as a laparoscopic instrument.

The surgical instrument 10 depicted in FIGS. 1 and 2 comprises a handle6, a shaft 8, and an articulating end effector 12 pivotally connected tothe shaft 8 at an articulation pivot 14. An articulation control 16 maybe provided adjacent to the handle 6 to effect rotation of the endeffector 12 about the articulation pivot 14. In the illustratedembodiment, the end effector 12 is configured to act as an endocutterfor clamping, severing and stapling tissue, although, in otherembodiments, different types of end effectors may be used, such as endeffectors for other types of surgical devices, such as graspers,cutters, staplers, clip appliers, access devices, drug/gene therapydevices, ultrasound, RF or laser devices, etc.

The handle 6 of the instrument 10 may include a closure trigger 18 and afiring trigger 20 for actuating the end effector 12. It will beappreciated that instruments having end effectors directed to differentsurgical tasks may have different numbers or types of triggers or othersuitable controls for operating the end effector 12. The end effector 12is shown separated from the handle 6 by a preferably elongate shaft 8.In one embodiment, a clinician or operator of the instrument 10 mayarticulate the end effector 12 relative to the shaft 8 by utilizing thearticulation control 16, as described in more detail in pending U.S.patent application Ser. No. 11/329,020 entitled “SURGICAL INSTRUMENTHAVING AN ARTICULATING END EFFECTOR” to Hueil et al., which isincorporated herein by reference.

The end effector 12 includes in this example, among other things, astaple channel 22 and a pivotally translatable clamping member, such asan anvil 24, which are maintained at a spacing that assures effectivestapling and severing of tissue clamped in the end effector 12. Thehandle 6 includes a pistol grip 26 towards which a closure trigger 18 ispivotally drawn by the clinician to cause clamping or closing of theanvil 24 toward the staple channel 22 of the end effector 12 to therebyclamp tissue positioned between the anvil 24 and channel 22. The firingtrigger 20 is farther outboard of the closure trigger 18. Once theclosure trigger 18 is locked in the closure position as furtherdescribed below, the firing trigger 20 may rotate slightly toward thepistol grip 26 so that it can be reached by the operator using one hand.Then the operator may pivotally draw the firing trigger 20 toward thepistol grip 26 to cause the stapling and severing of clamped tissue inthe end effector 12. In other embodiments, different types of clampingmembers besides the anvil 24 could be used, such as, for example, anopposing jaw, etc.

It will be appreciated that the terms “proximal” and “distal” are usedherein with reference to a clinician gripping the handle 6 of aninstrument 10. Thus, the end effector 12 is distal with respect to themore proximal handle 6. It will be further appreciated that, forconvenience and clarity, spatial terms such as “vertical” and“horizontal” are used herein with respect to the drawings. However,surgical instruments are used in many orientations and positions, andthese terms are not intended to be limiting and absolute.

The closure trigger 18 may be actuated first. Once the clinician issatisfied with the positioning of the end effector 12, the clinician maydraw back the closure trigger 18 to its fully closed, locked positionproximate to the pistol grip 26. The firing trigger 20 may then beactuated. The firing trigger 20 returns to the open position (shown inFIGS. 1 and 2) when the clinician removes pressure, as described morefully below. A release button on the handle 6, when depressed, mayrelease the locked closure trigger 18. The release button may beimplemented in various forms such as, for example, as a slide releasebutton 160 shown in FIG. 14, and/or button 172 shown in FIG. 16.

FIG. 3 is an exploded view of the end effector 12 according to variousembodiments. As shown in the illustrated embodiment, the end effector 12may include, in addition to the previously-mentioned channel 22 andanvil 24, a cutting instrument 32, a sled 33, a staple cartridge 34 thatis removably seated in the channel 22, and a helical screw shaft 36. Thecutting instrument 32 may be, for example, a knife. The anvil 24 may bepivotably opened and closed at a pivot point 25 connected to theproximate end of the channel 22. The anvil 24 may also include a tab 27at its proximate end that is inserted into a component of the mechanicalclosure system (described further below) to open and close the anvil 24.When the closure trigger 18 is actuated, that is, drawn in by a user ofthe instrument 10, the anvil 24 may pivot about the pivot point 25 intothe clamped or closed position. If clamping of the end effector 12 issatisfactory, the operator may actuate the firing trigger 20, which, asexplained in more detail below, causes the knife 32 and sled 33 totravel longitudinally along the channel 22, thereby cutting tissueclamped within the end effector 12. The movement of the sled 33 alongthe channel 22 causes the staples (not shown) of the staple cartridge 34to be driven through the severed tissue and against the closed anvil 24,which turns the staples to fasten the severed tissue. U.S. Pat. No.6,978,921, entitled “SURGICAL STAPLING INSTRUMENT INCORPORATING ANE-BEAM FIRING MECHANISM” to Shelton, IV et al., which is incorporatedherein by reference, provides more details about such two-stroke cuttingand fastening instruments. The sled 33 may be an integral component ofthe cartridge 34, such that when the knife 32 retracts following thecutting operation, the sled 33 does not retract.

It should be noted that although the embodiments of the instrument 10described herein employ an end effector 12 that staples the severedtissue, in other embodiments different techniques for fastening orsealing the severed tissue may be used. For example, end effectors thatuse RF energy or adhesives to fasten the severed tissue may also beused. U.S. Pat. No. 5,709,680 entitled “ELECTROSURGICAL HEMOSTATICDEVICE” to Yates et al., and U.S. Pat. No. 5,688,270 entitled“ELECTOSURGICAL HEMOSTATIC DEVICE WITH RECESSED AND/OR OFFSETELECTRODES” to Yates et al., both of which are incorporated herein byreference, disclose cutting instruments that uses RF energy to fastenthe severed tissue. U.S. patent application Ser. No. 11/267,811 entitled“SURGICAL STAPLING INSTRUMENTS STRUCTURED FOR DELIVERY OF MEDICALAGENTS” to Morgan et al., and U.S. patent application Ser. No.11/267,383 entitled “SURGICAL STAPLING INSTRUMENTS STRUCTURED FORPUMP-ASSISTED DELIVERY OF MEDICAL AGENTS” to Shelton IV et al., both ofwhich are also incorporated herein by reference, disclose cuttinginstruments that uses adhesives to fasten the severed tissue.Accordingly, although the description herein refers to cutting/staplingoperations and the like below, it should be recognized that this is anexemplary embodiment and is not meant to be limiting. Othertissue-fastening techniques may also be used.

FIGS. 4 and 5 are exploded views and FIG. 6 is a side view of the endeffector 12 and shaft 8 according to various embodiments. As shown inthe illustrated embodiment, the shaft 8 may include a proximate closuretube 40 and a distal closure tube 42 pivotably linked by a pivot links44. The distal closure tube 42 includes an opening 45 into which the tab27 on the anvil 24 is inserted in order to open and close the anvil 24,as further described below. Disposed inside the closure tubes 40, 42 maybe a proximate spine tube 46. Disposed inside the proximate spine tube46 may be a main rotational (or proximate) drive shaft 48 thatcommunicates with a secondary (or distal) drive shaft 50 via a bevelgear assembly 52. The secondary drive shaft 50 is connected to a drivegear 54 that engages a proximate drive gear 56 of the helical screwshaft 36. The vertical bevel gear 52 b may sit and pivot in an opening57 in the distal end of the proximate spine tube 46. A distal spine tube58 may be used to enclose the secondary drive shaft 50 and the drivegears 54, 56. Collectively, the main drive shaft 48, the secondary driveshaft 50, and the articulation assembly (e.g., the bevel gear assembly52 a-c) are sometimes referred to herein as the “main drive shaftassembly.”

A bearing 38, positioned at a distal end of the staple channel 22,receives the helical drive screw 36, allowing the helical drive screw 36to freely rotate with respect to the channel 22. The helical screw shaft36 may interface a threaded opening (not shown) of the knife 32 suchthat rotation of the shaft 36 causes the knife 32 to translate distallyor proximately (depending on the direction of the rotation) through thestaple channel 22. Accordingly, when the main drive shaft 48 is causedto rotate by actuation of the firing trigger 20 (as explained in moredetail below), the bevel gear assembly 52 a-c causes the secondary driveshaft 50 to rotate, which in turn, because of the engagement of thedrive gears 54, 56, causes the helical screw shaft 36 to rotate, whichcauses the knife driving member 32 to travel longitudinally along thechannel 22 to cut any tissue clamped within the end effector 12. Thesled 33 may be made of, for example, plastic, and may have a slopeddistal surface. As the sled 33 traverses the channel 22, the slopedforward surface may push up or drive the staples in the staple cartridge34 through the clamped tissue and against the anvil 24. The anvil 24turns the staples, thereby stapling the severed tissue. When the knife32 is retracted, the knife 32 and sled 33 may become disengaged, therebyleaving the sled 33 at the distal end of the channel 22.

Because of the lack of user feedback for the cutting/stapling operation,there is a general lack of acceptance among physicians of motor-driveninstruments where the cutting/stapling operation is actuated by merelypressing a button. In contrast, embodiments of the present inventionprovide a motor-driven endocutter with user-feedback of the deployment,force, and/or position of the cutting instrument in the end effector.

FIGS. 7-10 illustrate an exemplary embodiment of a motor-drivenendocutter, and in particular the handle 6 thereof, that providesuser-feedback regarding the deployment and loading force of the cuttinginstrument in the end effector. In addition, the embodiment may usepower provided by the user in retracting the firing trigger 20 to powerthe device (a so-called “power assist” mode). As shown in theillustrated embodiment, the handle 6 includes exterior lower side pieces59, 60 and exterior upper side pieces 61, 62 that fit together to form,in general, the exterior of the handle 6. A battery 64, such as a Li ionbattery, may be provided in the pistol grip portion 26 of the handle 6.The battery 64 powers a motor 65 disposed in an upper portion of thepistol grip portion 26 of the handle 6. According to variousembodiments, the motor 65 may be a DC brushed driving motor having amaximum rotation of, approximately, 5000 RPM. The motor 65 may drive a90° bevel gear assembly 66 comprising a first bevel gear 68 and a secondbevel gear 70. The bevel gear assembly 66 may drive a planetary gearassembly 72. The planetary gear assembly 72 may include a pinion gear 74connected to a drive shaft 76. The pinion gear 74 may drive a matingring gear 78 that drives a helical gear drum 80 via a drive shaft 82. Aring 84 may be threaded on the helical gear drum 80. Thus, when themotor 65 rotates, the ring 84 is caused to travel along the helical geardrum 80 by means of the interposed bevel gear assembly 66, planetarygear assembly 72 and ring gear 78.

The handle 6 may also include a run motor sensor 110 in communicationwith the firing trigger 20 to detect when the firing trigger 20 has beendrawn in (or “closed”) toward the pistol grip portion 26 of the handle 6by the operator to thereby actuate the cutting/stapling operation by theend effector 12. The sensor 110 may be a proportional sensor such as,for example, a rheostat or variable resistor. When the firing trigger 20is drawn in, the sensor 110 detects the movement, and sends anelectrical signal indicative of the voltage (or power) to be supplied tothe motor 65. When the sensor 110 is a variable resistor or the like,the rotation of the motor 65 may be generally proportional to the amountof movement of the firing trigger 20. That is, if the operator onlydraws or closes the firing trigger 20 in a little bit, the rotation ofthe motor 65 is relatively low. When the firing trigger 20 is fullydrawn in (or in the fully closed position), the rotation of the motor 65is at its maximum. In other words, the harder the user pulls on thefiring trigger 20, the more voltage is applied to the motor 65, causinggreater rates of rotation.

The handle 6 may include a middle handle piece 104 adjacent to the upperportion of the firing trigger 20. The handle 6 also may comprise a biasspring 112 connected between posts on the middle handle piece 104 andthe firing trigger 20. The bias spring 112 may bias the firing trigger20 to its fully open position. In that way, when the operator releasesthe firing trigger 20, the bias spring 112 will pull the firing trigger20 to its open position, thereby removing actuation of the sensor 110,thereby stopping rotation of the motor 65. Moreover, by virtue of thebias spring 112, any time a user closes the firing trigger 20, the userwill experience resistance to the closing operation, thereby providingthe user with feedback as to the amount of rotation exerted by the motor65. Further, the operator could stop retracting the firing trigger 20 tothereby remove force from the sensor 100, to thereby stop the motor 65.As such, the user may stop the deployment of the end effector 12,thereby providing a measure of control of the cutting/fasteningoperation to the operator.

The distal end of the helical gear drum 80 includes a distal drive shaft120 that drives a ring gear 122, which mates with a pinion gear 124. Thepinion gear 124 is connected to the main drive shaft 48 of the maindrive shaft assembly. In that way, rotation of the motor 65 causes themain drive shaft assembly to rotate, which causes actuation of the endeffector 12, as described above.

The ring 84 threaded on the helical gear drum 80 may include a post 86that is disposed within a slot 88 of a slotted arm 90. The slotted arm90 has an opening 92 its opposite end 94 that receives a pivot pin 96that is connected between the handle exterior side pieces 59, 60. Thepivot pin 96 is also disposed through an opening 100 in the firingtrigger 20 and an opening 102 in the middle handle piece 104.

In addition, the handle 6 may include a reverse motor (or end-of-strokesensor) 130 and a stop motor (or beginning-of-stroke) sensor 142. Invarious embodiments, the reverse motor sensor 130 may be a limit switchlocated at the distal end of the helical gear drum 80 such that the ring84 threaded on the helical gear drum 80 contacts and trips the reversemotor sensor 130 when the ring 84 reaches the distal end of the helicalgear drum 80. The reverse motor sensor 130, when activated, sends asignal to the motor 65 to reverse its rotation direction, therebywithdrawing the knife 32 of the end effector 12 following the cuttingoperation.

The stop motor sensor 142 may be, for example, a normally-closed limitswitch. In various embodiments, it may be located at the proximate endof the helical gear drum 80 so that the ring 84 trips the switch 142when the ring 84 reaches the proximate end of the helical gear drum 80.

In operation, when an operator of the instrument 10 pulls back thefiring trigger 20, the sensor 110 detects the deployment of the firingtrigger 20 and sends a signal to the motor 65 to cause forward rotationof the motor 65 at, for example, a rate proportional to how hard theoperator pulls back the firing trigger 20. The forward rotation of themotor 65 in turn causes the ring gear 78 at the distal end of theplanetary gear assembly 72 to rotate, thereby causing the helical geardrum 80 to rotate, causing the ring 84 threaded on the helical gear drum80 to travel distally along the helical gear drum 80. The rotation ofthe helical gear drum 80 also drives the main drive shaft assembly asdescribed above, which in turn causes deployment of the knife 32 in theend effector 12. That is, the knife 32 and sled 33 are caused totraverse the channel 22 longitudinally, thereby cutting tissue clampedin the end effector 12. Also, the stapling operation of the end effector12 is caused to happen in embodiments where a stapling-type end effectoris used.

By the time the cutting/stapling operation of the end effector 12 iscomplete, the ring 84 on the helical gear drum 80 will have reached thedistal end of the helical gear drum 80, thereby causing the reversemotor sensor 130 to be tripped, which sends a signal to the motor 65 tocause the motor 65 to reverse its rotation. This in turn causes theknife 32 to retract, and also causes the ring 84 on the helical geardrum 80 to move back to the proximate end of the helical gear drum 80.

The middle handle piece 104 includes a backside shoulder 106 thatengages the slotted arm 90 as best shown in FIGS. 8 and 9. The middlehandle piece 104 also has a forward motion stop 107 that engages thefiring trigger 20. The movement of the slotted arm 90 is controlled, asexplained above, by rotation of the motor 65. When the slotted arm 90rotates CCW as the ring 84 travels from the proximate end of the helicalgear drum 80 to the distal end, the middle handle piece 104 will be freeto rotate CCW. Thus, as the user draws in the firing trigger 20, thefiring trigger 20 will engage the forward motion stop 107 of the middlehandle piece 104, causing the middle handle piece 104 to rotate CCW. Dueto the backside shoulder 106 engaging the slotted arm 90, however, themiddle handle piece 104 will only be able to rotate CCW as far as theslotted arm 90 permits. In that way, if the motor 65 should stoprotating for some reason, the slotted arm 90 will stop rotating, and theuser will not be able to further draw in the firing trigger 20 becausethe middle handle piece 104 will not be free to rotate CCW due to theslotted arm 90.

FIGS. 41 and 42 illustrate two states of a variable sensor that may beused as the run motor sensor 110 according to various embodiments of thepresent invention. The sensor 110 may include a face portion 280, afirst electrode (A) 282, a second electrode (B) 284, and a compressibledielectric material 286 (e.g., EAP) between the electrodes 282, 284. Thesensor 110 may be positioned such that the face portion 280 contacts thefiring trigger 20 when retracted. Accordingly, when the firing trigger20 is retracted, the dielectric material 286 is compressed, as shown inFIG. 42, such that the electrodes 282, 284 are closer together. Sincethe distance “b” between the electrodes 282, 284 is directly related tothe impedance between the electrodes 282, 284, the greater the distancethe more impedance, and the closer the distance the less impedance. Inthat way, the amount that the dielectric material 286 is compressed dueto retraction of the firing trigger 20 (denoted as force “F” in FIG. 42)is proportional to the impedance between the electrodes 282, 284, whichcan be used to proportionally control the motor 65.

Components of an exemplary closure system for closing (or clamping) theanvil 24 of the end effector 12 by retracting the closure trigger 18 arealso shown in FIGS. 7-10. In the illustrated embodiment, the closuresystem includes a yoke 250 connected to the closure trigger 18 by a pin251 that is inserted through aligned openings in both the closuretrigger 18 and the yoke 250. A pivot pin 252, about which the closuretrigger 18 pivots, is inserted through another opening in the closuretrigger 18 which is offset from where the pin 251 is inserted throughthe closure trigger 18. Thus, retraction of the closure trigger 18causes the upper part of the closure trigger 18, to which the yoke 250is attached via the pin 251, to rotate CCW. The distal end of the yoke250 is connected, via a pin 254, to a first closure bracket 256. Thefirst closure bracket 256 connects to a second closure bracket 258.Collectively, the closure brackets 256, 258 define an opening in whichthe proximal end of the proximate closure tube 40 (see FIG. 4) is seatedand held such that longitudinal movement of the closure brackets 256,258 causes longitudinal motion by the proximate closure tube 40. Theinstrument 10 also includes a closure rod 260 disposed inside theproximate closure tube 40. The closure rod 260 may include a window 261into which a post 263 on one of the handle exterior pieces, such asexterior lower side piece 59 in the illustrated embodiment, is disposedto fixedly connect the closure rod 260 to the handle 6. In that way, theproximate closure tube 40 is capable of moving longitudinally relativeto the closure rod 260. The closure rod 260 may also include a distalcollar 267 that fits into a cavity 269 in proximate spine tube 46 and isretained therein by a cap 271 (see FIG. 4).

In operation, when the yoke 250 rotates due to retraction of the closuretrigger 18, the closure brackets 256, 258 cause the proximate closuretube 40 to move distally (i.e., away from the handle 6 end of theinstrument 10), which causes the distal closure tube 42 to movedistally, which causes the anvil 24 to rotate about the pivot point 25into the clamped or closed position. When the closure trigger 18 isunlocked from the locked position, the proximate closure tube 40 iscaused to slide proximally, which causes the distal closure tube 42 toslide proximally, which, by virtue of the tab 27 being inserted in theopening 45 of the distal closure tube 42, causes the anvil 24 to pivotabout the pivot point 25 into the open or unclamped position. In thatway, by retracting and locking the closure trigger 18, an operator mayclamp tissue between the anvil 24 and channel 22, and may unclamp thetissue following the cutting/stapling operation by unlocking the closuretrigger 18 from the locked position.

FIG. 11 is a schematic diagram of an electrical circuit of theinstrument 10 according to various embodiments of the present invention.When an operator initially pulls in the firing trigger 20 after lockingthe closure trigger 18, the sensor 110 is activated, allowing current toflow therethrough. If the normally-open reverse motor sensor switch 130is open (meaning the end of the end effector stroke has not beenreached), current will flow to a single pole, double throw relay 132.Since the reverse motor sensor switch 130 is not closed, coil 134 of therelay 132 will not be energized, so the relay 132 will be in itsde-energized state. The electrical circuit further includes lockoutsensor switches 136 a-d collectively defining an interlock circuit 137through which current from the relay 132, when de-energized, must passin order for electrical operation of the motor 65 to be initiated. Eachlockout sensor switch 136 a-d is configured to maintain an open (i.e.,non-conductive) switch state or a closed (i.e., conductive) switch stateresponsive to the presence or absence, respectively, of a correspondingcondition. Any of the corresponding conditions, if present when theinstrument 10 is fired, may result in an unsatisfactory cutting andstapling operation and/or damage to the instrument 10. Conditions towhich the lockout sensor switches 136 a-d may respond include, forexample, the absence of the staple cartridge 34 in the channel 22, thepresence of a spent (e.g., previously fired) staple cartridge 34 in thechannel 22, and an open (or otherwise insufficiently closed) position ofthe anvil 24 with respect to the channel 22. Other conditions to whichthe lockout sensor switches 136 a-d may respond, such as component wear,may be inferred based upon an accumulated number of firing operationsproduced by the instrument 10. Accordingly, if any of these conditionsexists, the corresponding lockout sensor switches 136 a-d maintain anopen switch state, thus preventing passage of the current necessary toinitiate operation of the motor 65. Passage of current by the lockoutsensors 136 a-d is allowed only after all of the conditions have beenremedied. It will be appreciated that the above-described conditions areprovided by way of example only, and that additional lockout sensorswitches for responding to other conditions detrimental to operation ofthe instrument 10 may be provided. It will similarly be appreciated thatfor embodiments in which one or more of the above-described conditionsmay not exist or are of no concern, the number of lockout sensorswitches may be fewer than that depicted.

As shown in FIG. 11, the lockout sensor switch 136 a may be implementedusing a normally-open switch configuration such that a closed switchstate is maintained when the staple cartridge 34 is in a positioncorresponding to its proper receipt by the channel 22. When the staplecartridge 34 is not installed in the channel 22, or is installedimproperly (e.g., mis-aligned), the lockout sensor switch 136 amaintains an open switch state.

Lockout sensor switch 136 b may be implemented using a normally-openswitch configuration such that a closed switch state is maintained onlywhen an unspent staple cartridge 34 (i.e., a staple cartridge 34 havinga sled 33 in the unfired position) is present in the channel 22. Thepresence of a spent staple cartridge 34 in the channel 22 causes thelockout sensor switch 136 b to maintain an open switch state.

Lockout sensor switch 136 c may be implemented using a normally-openswitch configuration such that a closed switch state is maintained whenthe anvil 24 is in a closed position with respect to the channel 22. Asdiscussed in further detail below, the lockout sensor switch 136 c maybe controlled in accordance with a time delay feature wherein a closedswitch state is maintained only after the anvil 24 is in the closedposition for a pre-determined period of time.

Lockout sensor switch 136 d may be implemented using a normally-closedswitch configuration such that a closed switch state is maintained onlywhen an accumulated number of firings produced by the instrument 10 isless than a pre-determined number. As discussed in further detail below,the lockout sensor switch 136 d may be in communication with a counter304 configured for maintaining a count representative of the accumulatednumber of firing operations performed by the instrument, comparing thecount to the pre-determined number, and controlling the switch state ofthe lockout sensor switch 136 d based upon the comparison.

According to various embodiments, the interlock circuit 137 may compriseone or more indicators visible to the user of the instrument 10 fordisplaying a status of at least one of the lockout sensor switches 136a-d. As shown in FIG. 11, for example, each lockout sensor switch 136a-d may have a green LED 139 a and a red LED 139 b associated therewith.The interlock circuit 137 may be configured such that the LEDs 139 a,bare energized when the corresponding lockout sensor switch 136 a-d ismaintained in the closed and open switch states, respectively. It willbe appreciated that the lockout sensor switches 136 a-d may comprise oneor more auxiliary switch contacts (not shown) having a switchconfiguration suitable for operating the LEDs 139 a,b in the mannerdescribed above.

FIGS. 43A-44C illustrate mounting arrangements and configurations of thelockout sensor switches 136 a-d of the interlock circuit 137 accordingto various embodiments of the present invention. As shown in FIG. 43A,the lockout sensor switch 136 a may comprise a first switch contact 288a and a second switch contact 288 b disposed upon an inner wall of thechannel 22 and electrically isolated therefrom. The respective positionsof the first and second switch contacts 288 a,b are such that when thestaple cartridge 34 is in a position corresponding to its proper receiptby the channel 22, a conductive or semi-conductive portion 290 of thestaple cartridge 34 (exemplified as a metal tray portion of the staplecartridge 34) contacts the first and second switch contacts 288 a,b toestablish a conductive path therebetween. As best seen in FIG. 43B, eachswitch contact 288 a,b may comprise a rounded profile for minimizingmechanical resistance to the staple cartridge 34 when received by thechannel 22 and for enabling affirmative electrical contact with theconductive portion 290 thereof. The conductive portion 290 thus operatesto maintain the lockout sensor switch 136 a in a closed switch state.Although the switch contacts 288 a,b are shown adjacently positioned ona sidewall portion of the channel 22, it will be appreciated that eachswitch contact 288 a,b may generally be located at any location withinthe channel 22 where suitable electrical contact with the conductivemember 290 is possible. It will further be appreciated that the lockoutsensor switch 136 a may alternatively be implemented using aconventional contact-actuated limit switch. According to suchembodiments, the limit switch may be positioned such that staplecartridge 34, when received by the channel 22, mechanically actuates thelimit switch such that a closed switch state is maintained. It willfurther be appreciated that the lockout sensor switch 136 a may also beimplemented using a conventional non-contact actuated limit switch, suchas, for example, a magnetic reed limit switch or a Hall effect proximityswitch. According to such embodiments, the staple cartridge 34 maycomprise a magnet suitable for causing the lockout sensor switch 136 ato maintain a closed switch state when the staple cartridge 34 isinstalled.

As best seen in FIG. 43B, the lockout sensor switch 136 b may be mountedon an interior bottom surface of the channel 22. According to variousembodiments and as shown, the lockout sensor switch 136 b may beimplemented using a contact-actuated limit switch of a conventionaldesign that is suitable for detecting linear movement. Orientation ofthe lockout sensor switch 136 b may be such that an actuated portionthereof extends upwardly from the bottom interior surface of the channel22. The position of the lockout sensor switch 136 b on the bottomsurface of the channel 22 is such that when an unspent staple cartridge34 is installed, a bottom portion of the sled 33 mechanically actuatesthe lockout sensor switch 136 b and causes a closed switch state to bemaintained thereby. Accordingly, the presence of an unspent staplecartridge 34 (i.e., a staple cartridge having a sled 33 in the unfiredposition) enables the passage of current through the lockout sensorswitch 136 b. It will be appreciated the lockout sensor switch 136 b mayinstead be implemented using a non-contact actuated switch (e.g., amagnetic reed limit switch or a Hall effect proximity switch). For suchimplementations, the sled 33 may comprise a magnetized portion, forexample, that actuates the lockout sensor switch 136 b when the sled 33is present in the un-fired position.

As shown in FIG. 44A, the lockout sensor switch 136 c is positionedadjacent a distal end of one of the pivot recesses 296 defined by theproximal end of the channel 22 for engaging a corresponding pivot point25 of the anvil 24. According to various embodiments and as shown, thelockout sensor switch 136 c may be implemented using a contact-actuatedlimit switch of a conventional design that is suitable for detectinglinear movement. It will be appreciated, however, that anon-contact-actuated limit switch may be used instead. Orientation ofthe lockout sensor switch 136 c may be such that an actuated portionthereof extends slightly over the distal end of the corresponding pivotrecess 296. When the anvil 24 is in an open position with respect to thechannel 22 (as shown in FIG. 44A), the pivot point 25 is positioned atthe proximal end of the pivot recess 296. Closure of the anvil 24 causesthe pivot point 25 to move to the distal end of the pivot recess 296.The resulting contact of the pivot point 25 with the actuated portion ofthe lockout sensor switch 136 c causes the lockout sensor switch 136 cto maintain a closed switch state, thus enabling the passage of currenttherethrough.

According to other embodiments and as shown in FIG. 44B, the lockoutsensor switch 136 c may instead be configured to maintain a closedswitch state responsive to an electrical signal. The electrical signalmay be, for example, an analog signal generated by a force sensor 298disposed on a bottom inner surface of the channel 22 that represents amagnitude of the clamping force applied by the anvil 24. The closedposition of the anvil 24 may thus be inferred if the analog signal issufficiently large in magnitude. Accordingly, the analog signal may bereceived by a comparator circuit 141 configured to determine if themagnitude exceeds a pre-determined threshold stored therein. If thethreshold is exceeded, indicating closure of the anvil 24, thecomparator circuit 141 causes the lockout sensor switch 136 c tomaintain a closed switch state, thus enabling the passage of currenttherethrough. If the magnitude of the analog signal is less than thepre-determined threshold, indicating that the anvil 24 is notsufficiently closed, the comparator circuit 141 causes the lockoutsensor switch 136 c to maintain an open switch state, thus preventingthe passage of current therethrough. Although shown separately, it willbe appreciated that the comparator circuit 141 may be integral with thelockout sensor switch 136 c so as to form a common device. It willfurther be appreciated that the pre-defined threshold stored by thecomparator circuit 141 may be adjusted as necessary to reflect the forceindicative of closure of the anvil 24 for different cutting and staplingoperations.

In certain instances, it may be necessary or otherwise desirable todelay commencement of a firing operation for a period of time subsequentto closure of the anvil 24. For example, the introduction of a delaybetween the clamping and firing operations may serve to improve thestabilization of clamped tissue. Accordingly, with reference to FIG.44C, embodiments of the present invention may comprise a timer 300having a pre-set time delay (e.g., 12 seconds) and configured forcontrolling the switch state of the lockout sensor switch 136 c inaccordance with a time-based position of the anvil 24. Although shownseparately, it will be appreciated that the timer 300 may be integralwith the lockout sensor switch 136 c so as to form a common device(e.g., an on-delay timer). Preferably, the timer 300 is implemented asan electronic device, although it will be appreciated that a mechanicaltimer may be used instead. A normally-open limit switch 302 configuredin a manner identical to that of FIG. 44A may be connected to the timer300 such that timing is initiated when the anvil 24 is in a closedposition with respect to the channel 22. Upon expiration of the pre-settime delay, the timer 300 causes the lockout sensor switch 136 c tomaintain a closed switch state, thus enabling the passage of currenttherethrough. The timer 300 may be reset in response to the transitionof the limit switch 302 to an open switch state (i.e., when the anvil 24is in the open position). It will be appreciated that the pre-set timedelay of the timer 300 may be selectively adjusted (e.g., using anintegral potentiometer adjustment) as required.

Referring again to FIG. 11, the electrical circuit may comprise acounter 304 configured to maintain a count representative of theaccumulated number of firing operations performed by the instrument 10and, based on the count, to control the switch state of the lockoutsensor switch 136 d. Although shown separately, it will be appreciatedthat counter 304 may be integral with the lockout sensor switch 136 d soas to form a common device. Preferably, the counter 304 is implementedas an electronic device having an input for incrementing the maintainedcount based upon the transition of a discrete electrical signal providedthereto. It will be appreciated that a mechanical counter configured formaintaining the count based upon a mechanical input (e.g., retraction ofthe firing trigger 20) may be used instead. When implemented as anelectronic device, any discrete signal present in the electrical circuitthat transitions once for each firing operation may be utilized for thecounter 304 input. As shown in FIG. 11, for example, the discreteelectrical signal resulting from actuation of the end-of-stroke sensor130 may be utilized. The counter 304 may control the switch state oflockout sensor switch 136 d such that a closed switch state ismaintained when the maintained count is less than a pre-determinednumber stored within the counter 304. When the maintained count is equalto the pre-determined number, the counter 304 causes the lockout sensorswitch 136 d to maintain an open switch state, thus preventing thepassage of current therethrough. It will be appreciated that thepre-determined number stored by the counter 304 may be selectivelyadjusted as required. According to various embodiments, the counter 304may be in communication with a display 305, such as an LCD display,integral to the instrument 10 for indicating to a user either themaintained count or the difference between the pre-determined number andthe maintained count.

When the lockout sensor switches 136 a-d collectively maintain a closedswitch state, a single pole, single throw relay 138 is energized. Whenthe relay 138 is energized, current flows through the relay 138, throughthe variable resistor sensor 110, and to the motor 65 via a double pole,double throw relay 140, thereby powering the motor 65 and allowing it torotate in the forward direction. Because the output of the relay 138,once energized, maintains the relay 138 in an energized state untilrelay 132 is energized, the interlock circuit 137 will not function toprevent operation of the motor 65 once initiated, even if one or more ofthe interlock sensor switches 136 a-d subsequently maintains an openswitch state. In other embodiments, however, it may be necessary orotherwise desirable to connect the interlock circuit 137 and the relay138 such that one or more the lockout sensor switches 136 a-d mustmaintain a closed switch state in order to sustain operation of themotor 65 once initiated.

Rotation of the motor in the forward direction causes the ring 84 tomove distally and thereby de-actuate the stop motor sensor switch 142.Because the switch 142 is normally-closed, solenoid 306 is energized.The solenoid 306 may be a conventional push-type solenoid that, whenenergized, causes a plunger (not shown) to be axially extended. Asdiscussed below in connection with FIGS. 14-22, extension of the plungermay operate to retain the closure trigger 18 in the retracted position,thus preventing the anvil 24 from opening while a firing operation is inprogress (i.e., while the switch 142 is not actuated). Uponde-energization of the solenoid 306, the plunger is retracted such thatmanual release of the closure trigger 18 is possible. The switch 142 andthe solenoid 306 thus define an interlock circuit 307 that preventspivotal movement of the anvil 24 relative to the channel 22 duringmovement of the cutting instrument 32. In certain embodiments, theinterlock circuit 307 includes an electromechanical actuator 306 (e.g.,solenoid 306) configured to prevent opening of the anvil 24 relative tothe channel 22 during movement of the cutting instrument 32.

When the end effector 12 reaches the end of its stroke, the reversemotor sensor 130 will be activated, thereby closing the switch 130 andenergizing the relay 132. This causes the relay 132 to assume itsenergized state (not shown in FIG. 11), which causes current to bypassthe interlock circuit 137 and variable resistor 110, and instead causescurrent to flow to both the normally-closed double pole, double throwrelay 140 and back to the motor 65, but in a manner, via the relay 140,that causes the motor 65 to reverse its rotational direction.

Because the stop motor sensor switch 142 is normally-closed, currentwill flow back to the relay 132 to keep it energized until the switch142 opens. When the knife 32 is fully retracted, the stop motor sensorswitch 142 is activated, causing the switch 142 to open, therebyremoving power from the motor 65 and de-energizing the solenoid 306.

In other embodiments, rather than a proportional-type sensor 110, anon-off type sensor could be used. In such embodiments, the rate ofrotation of the motor 65 would not be proportional to the force appliedby the operator. Rather, the motor 65 would generally rotate at aconstant rate. But the operator would still experience force feedbackbecause the firing trigger 20 is geared into the gear drive train.

FIG. 12 is a side-view of the handle 6 of a power-assist motorizedendocutter according to another embodiment. The embodiment of FIG. 12 issimilar to that of FIGS. 7-10 except that in the embodiment of FIG. 12,there is no slotted arm 90 connected to the ring 84 threaded on thehelical gear drum 80. Instead, in the embodiment of FIG. 12, the ring 84includes a sensor portion 114 that moves with the ring 84 as the ring 84advances down (and back) on the helical gear drum 80. The sensor portion114 includes a notch 116. The reverse motor sensor 130 may be located atthe distal end of the notch 116 and the stop motor sensor 142 may belocated at the proximate end of the notch 116. As the ring 84 moves downthe helical gear drum 80 (and back), the sensor portion 114 moves withit. Further, as shown in FIG. 12, the middle piece 104 may have an arm118 that extends into the notch 116.

In operation, as an operator of the instrument 10 retracts in the firingtrigger 20 toward the pistol grip 26, the run motor sensor 110 detectsthe motion and sends a signal to power the motor 65, which causes, amongother things, the helical gear drum 80 to rotate. As the helical geardrum 80 rotates, the ring 84 threaded on the helical gear drum 80advances (or retracts, depending on the rotation). Also, due to thepulling in of the firing trigger 20, the middle piece 104 is caused torotate CCW with the firing trigger 20 due to the forward motion stop 107that engages the firing trigger 20. The CCW rotation of the middle piece104 cause the arm 118 to rotate CCW with the sensor portion 114 of thering 84 such that the arm 118 stays disposed in the notch 116. When thering 84 reaches the distal end of the helical gear drum 80, the arm 118will contact and thereby trip the reverse motor sensor 130. Similarly,when the ring 84 reaches the proximate end of the helical gear drum 80,the arm 118 will contact and thereby trip the stop motor sensor 142.Such actions may reverse and stop the motor 65, respectively, asdescribed above.

FIG. 13 is a side-view of the handle 6 of a power-assist motorizedendocutter according to another embodiment. The embodiment of FIG. 13 issimilar to that of FIGS. 7-10 except that in the embodiment of FIG. 13,there is no slot in the arm 90. Instead, the ring 84 threaded on thehelical gear drum 80 includes a vertical channel 126. Instead of a slot,the arm 90 includes a post 128 that is disposed in the channel 126. Asthe helical gear drum 80 rotates, the ring 84 threaded on the helicalgear drum 80 advances (or retracts, depending on the rotation). The arm90 rotates CCW as the ring 84 advances due to the post 128 beingdisposed in the channel 126, as shown in FIG. 13.

As mentioned above, in using a two-stroke motorized instrument, theoperator first pulls back and locks the closure trigger 18. FIGS. 14 and15 show one embodiment of a way to lock the closure trigger 18 to thepistol grip portion 26 of the handle 6. In the illustrated embodiment,the pistol grip portion 26 includes a hook 150 that is biased to rotateCCW about a pivot point 151 by a torsion spring 152. Also, the closuretrigger 18 includes a closure bar 154. As the operator draws in theclosure trigger 18, the closure bar 154 engages a sloped portion 156 ofthe hook 150, thereby rotating the hook 150 upward (or CW in FIGS.14-15) until the closure bar 154 completely passes the sloped portion156 into a recessed notch 158 of the hook 150, which locks the closuretrigger 18 in place. The operator may release the closure trigger 18 bypushing down on a slide button release 160 on the back or opposite sideof the pistol grip portion 26. Pushing down the slide button release 160rotates the hook 150 CW such that the closure bar 154 is released fromthe recessed notch 158. In order to prevent the anvil 24 frominadvertently being opened while a firing operation is in progress, thesolenoid 306 may be positioned within the pistol grip 26 such that theplunger 308 of the solenoid 306, when energized, is received into acorresponding opening 163 of the slide button release 160. Accordingly,the slide button release 160 is locked in place such that manipulationof the slide button release 160 is prevented until the plunger 308 isretracted from the opening 163 at the conclusion of the firingoperation.

FIG. 16 shows another closure trigger locking mechanism according tovarious embodiments. In the embodiment of FIG. 16, the closure trigger18 includes a wedge 160 having an arrow-head portion 161. The arrow-headportion 161 is biased downward (or CW) by a leaf spring 162. The wedge160 and leaf spring 162 may be made from, for example, molded plastic.When the closure trigger 18 is retracted, the arrow-head portion 161 isinserted through an opening 164 in the pistol grip portion 26 of thehandle 6. A lower chamfered surface 166 of the arrow-head portion 161engages a lower sidewall 168 of the opening 164, forcing the arrow-headportion 161 to rotate CCW. Eventually the lower chamfered surface 166fully passes the lower sidewall 168, removing the CCW force on thearrow-head portion 161, causing the lower sidewall 168 to slip into alocked position in a notch 170 behind the arrow-head portion 161.

To unlock the closure trigger 18, a user presses down on a button 172 onthe opposite side of the closure trigger 18, causing the arrow-headportion 161 to rotate CCW and allowing the arrow-head portion 161 toslide out of the opening 164. In order to prevent the anvil 24 frominadvertently being opened while a firing operation is in progress, thesolenoid 306 may be positioned within the pistol grip 26 such that theplunger 308 of the solenoid 306, when energized, is received into acorresponding opening 173 defined by the arrow-head portion 161. Whenreceived into the opening 173, the plunger 308 operates to prevent CCWrotation of the arrow-head portion 161. Accordingly, inadvertentmanipulation of the button 172 by the user is prevented by the useruntil the plunger 308 is retracted from the opening 173 at theconclusion of the firing operation.

FIGS. 17-22 show a closure trigger locking mechanism according toanother embodiment. As shown in this embodiment, the closure trigger 18includes a flexible longitudinal arm 176 that includes a lateral pin 178extending therefrom. The arm 176 and pin 178 may be made from moldedplastic, for example. The pistol grip portion 26 of the handle 6includes an opening 180 with a laterally extending wedge 182 disposedtherein. When the closure trigger 18 is retracted, the pin 178 engagesthe wedge 182, and the pin 178 is forced downward (i.e., the arm 176 isrotated CW) by the lower surface 184 of the wedge 182, as shown in FIGS.17 and 18. When the pin 178 fully passes the lower surface 184, the CWforce on the arm 176 is removed, and the pin 178 is rotated CCW suchthat the pin 178 comes to rest in a notch 186 behind the wedge 182, asshown in FIG. 19, thereby locking the closure trigger 18. The pin 178 isfurther held in place in the locked position by a flexible stop 188extending from the wedge 184.

To unlock the closure trigger 18, the operator may further squeeze theclosure trigger 18, causing the pin 178 to engage a sloped backwall 190of the opening 180, forcing the pin 178 upward past the flexible stop188, as shown in FIGS. 20 and 21. The pin 178 is then free to travel outan upper channel 192 in the opening 180 such that the closure trigger 18is no longer locked to the pistol grip portion 26, as shown in FIG. 22.In order to prevent the anvil 24 from inadvertently being opened while afiring operation is in progress, the solenoid 306 may be positionedwithin the pistol grip 26 such that the plunger 308 of the solenoid 306,when energized, is received into the upper channel 192. When receivedinto the upper channel 192, the plunger 308 operates to prevent passageof the pin 178 therethrough. Accordingly, unlocking the closure trigger18 is prevented until the plunger 308 is retracted from the upperchannel 192 at the conclusion of the firing operation.

FIGS. 23A-B show a universal joint (“u-joint”) 195. The second piece195-2 of the u-joint 195 rotates in a horizontal plane in which thefirst piece 195-1 lies. FIG. 23A shows the u-joint 195 in a linear(180°) orientation and FIG. 23B shows the u-joint 195 at approximately a150° orientation. The u-joint 195 may be used instead of the bevel gears52 a-c (see FIG. 4, for example) at the articulation point 14 of themain drive shaft assembly to articulate the end effector 12. FIGS. 24A-Bshow a torsion cable 197 that may be used in lieu of both the bevelgears 52 a-c and the u-joint 195 to realize articulation of the endeffector 12.

FIGS. 25-31 illustrate another embodiment of a motorized, two-strokesurgical cutting and fastening instrument 10 with power assist accordingto another embodiment of the present invention. The embodiment of FIGS.25-31 is similar to that of FIGS. 6-10 except that instead of thehelical gear drum 80, the embodiment of FIGS. 25-31 includes analternative gear drive assembly. The embodiment of FIGS. 25-31 includesa gear box assembly 200 including a number of gears disposed in a frame201, wherein the gears are connected between the planetary gear 72 andthe pinion gear 124 at the proximate end of the drive shaft 48. Asexplained further below, the gear box assembly 200 provides feedback tothe user via the firing trigger 20 regarding the deployment and loadingforce of the end effector 12. Also, the user may provide power to thesystem via the gear box assembly 200 to assist the deployment of the endeffector 12. In that sense, like the embodiments described above, theembodiment of FIGS. 25-31 is another power assist, motorized instrument10 that provides feedback to the user regarding the loading forceexperienced by the cutting instrument 32.

In the illustrated embodiment, the firing trigger 20 includes twopieces: a main body portion 202 and a stiffening portion 204. The mainbody portion 202 may be made of plastic, for example, and the stiffeningportion 204 may be made out of a more rigid material, such as metal. Inthe illustrated embodiment, the stiffening portion 204 is adjacent tothe main body portion 202, but according to other embodiments, thestiffening portion 204 could be disposed inside the main body portion202. A pivot pin 207 may be inserted through openings in the firingtrigger pieces 202, 204 and may be the point about which the firingtrigger 20 rotates. In addition, a spring 222 may bias the firingtrigger 20 to rotate in a CCW direction. The spring 222 may have adistal end connected to a pin 224 that is connected to the pieces 202,204 of the firing trigger 20. The proximate end of the spring 222 may beconnected to one of the handle exterior lower side pieces 59, 60.

In the illustrated embodiment, both the main body portion 202 and thestiffening portion 204 include gear portions 206, 208 (respectively) attheir upper end portions. The gear portions 206, 208 engage a gear inthe gear box assembly 200, as explained below, to drive the main driveshaft assembly and to provide feedback to the user regarding thedeployment of the end effector 12.

The gear box assembly 200 may include as shown, in the illustratedembodiment, six (6) gears. A first gear 210 of the gear box assembly 200engages the gear portions 206, 208 of the firing trigger 20. Inaddition, the first gear 210 engages a smaller second gear 212, thesmaller second gear 212 being coaxial with a large third gear 214. Thethird gear 214 engages a smaller fourth gear 216, the smaller fourthgear 216 being coaxial with a fifth gear 218. The fifth gear 218 is a90° bevel gear that engages a mating 90° bevel gear 220 (best shown inFIG. 31) that is connected to the pinion gear 124 that drives the maindrive shaft 48.

In operation, when the user retracts the firing trigger 20, a run motorsensor (not shown) is activated, which may provide a signal to the motor65 to rotate at a rate proportional to the extent or force with whichthe operator is retracting the firing trigger 20. This causes the motor65 to rotate at a speed proportional to the signal from the sensor. Thesensor is not shown for this embodiment, but it could be similar to therun motor sensor 110 described above. The sensor could be located in thehandle 6 such that it is depressed when the firing trigger 20 isretracted. Also, instead of a proportional-type sensor, an on/off typesensor may be used.

Rotation of the motor 65 causes the bevel gears 66, 70 to rotate, whichcauses the planetary gear 72 to rotate, which causes, via the driveshaft 76, the ring gear 122 to rotate. The ring gear 122 meshes with thepinion gear 124, which is connected to the main drive shaft 48. Thus,rotation of the pinion gear 124 drives the main drive shaft 48, whichcauses actuation of the cutting/stapling operation of the end effector12.

Forward rotation of the pinion gear 124 in turn causes the bevel gear220 to rotate, which causes, by way of the rest of the gears of the gearbox assembly 200, the first gear 210 to rotate. The first gear 210engages the gear portions 206, 208 of the firing trigger 20, therebycausing the firing trigger 20 to rotate CCW when the motor 65 providesforward drive for the end effector 12 (and to rotate CCW when the motor65 rotates in reverse to retract the end effector 12). In that way, theuser experiences feedback regarding loading force and deployment of theend effector 12 by way of the user's grip on the firing trigger 20.Thus, when the user retracts the firing trigger 20, the operator willexperience a resistance related to the load force experienced by the endeffector 12. Similarly, when the operator releases the firing trigger 20after the cutting/stapling operation so that it can return to itsoriginal position, the user will experience a CW rotation force from thefiring trigger 20 that is generally proportional to the reverse speed ofthe motor 65.

It should also be noted that in this embodiment the user can apply force(either in lieu of or in addition to the force from the motor 65) toactuate the main drive shaft assembly (and hence the cutting/staplingoperation of the end effector 12) through retracting the firing trigger20. That is, retracting the firing trigger 20 causes the gear portions206, 208 to rotate CCW, which causes the gears of the gear box assembly200 to rotate, thereby causing the pinion gear 124 to rotate, whichcauses the main drive shaft 48 to rotate.

Although not shown in FIGS. 25-31, the instrument 10 may further includereverse motor and stop motor sensors. As described above, the reversemotor and stop motor sensors may detect, respectively, the end of thecutting stroke (full deployment of the knife 32 and sled 33) and the endof retraction operation (full retraction of the knife 32). A circuitsimilar to that described above in connection with FIG. 11 may be usedto appropriately power the motor 65.

FIGS. 32-36 illustrate a two-stroke, motorized surgical cutting andfastening instrument 10 with power assist according to anotherembodiment. The embodiment of FIGS. 32-36 is similar to that of FIGS.25-31 except that in the embodiment of FIGS. 32-36, the firing trigger20 includes a lower portion 228 and an upper portion 230. Both portions228, 230 are connected to and pivot about a pivot pin 207 that isdisposed through each portion 228, 230. The upper portion 230 includes agear portion 232 that engages the first gear 210 of the gear boxassembly 200. The spring 222 is connected to the upper portion 230 suchthat the upper portion is biased to rotate in the CW direction. Theupper portion 230 may also include a lower arm 234 that contacts anupper surface of the lower portion 228 of the firing trigger 20 suchthat when the upper portion 230 is caused to rotate CW the lower portion228 also rotates CW, and when the lower portion 228 rotates CCW theupper portion 230 also rotates CCW. Similarly, the lower portion 228includes a rotational stop 238 that engages a lower shoulder of theupper portion 230. In that way, when the upper portion 230 is caused torotate CCW the lower portion 228 also rotates CCW, and when the lowerportion 228 rotates CW the upper portion 230 also rotates CW.

The illustrated embodiment also includes the run motor sensor 110 thatcommunicates a signal to the motor 65 that, in various embodiments, maycause the motor 65 to rotate at a speed proportional to the forceapplied by the operator when retracting the firing trigger 20. Thesensor 110 may be, for example, a rheostat or some other variableresistance sensor, as explained herein. In addition, the instrument 10may include a reverse motor sensor 130 that is tripped or switched whencontacted by a front face 242 of the upper portion 230 of the firingtrigger 20. When activated, the reverse motor sensor 130 sends a signalto the motor 65 to reverse direction. Also, the instrument 10 mayinclude a stop motor sensor 142 that is tripped or actuated whencontacted by the lower portion 228 of the firing trigger 20. Whenactivated, the stop motor sensor 142 sends a signal to stop the reverserotation of the motor 65.

In operation, when an operator retracts the closure trigger 18 into thelocked position, the firing trigger 20 is retracted slightly (throughmechanisms known in the art, including U.S. Pat. No. 6,905,057 entitled“SURGICAL STAPLING INSTRUMENT INCORPORATING A FIRING MECHANISM HAVING ALINKED RACK TRANSMISSION” to Swayze et al., which is incorporated hereinby reference) so that the user can grasp the firing trigger 20 toinitiate the cutting/stapling operation, as shown in FIGS. 32 and 33. Atthat point, as shown in FIG. 33, the gear portion 232 of the upperportion 230 of the firing trigger 20 moves into engagement with thefirst gear 210 of the gear box assembly 200. When the operator retractsthe firing trigger 20, according to various embodiments, the firingtrigger 20 may rotate a small amount, such as five degrees, beforetripping the run motor sensor 110, as shown in FIG. 34. Activation ofthe sensor 110 causes the motor 65 to forward rotate at a rateproportional to the retraction force applied by the operator. Theforward rotation of the motor 65 causes, as described above, the maindrive shaft 48 to rotate, which causes the knife 32 in the end effector12 to be deployed (i.e., begin traversing the channel 22). Rotation ofthe pinion gear 124, which is connected to the main drive shaft 48,causes the gears 210-220 in the gear box assembly 200 to rotate. Sincethe first gear 210 is in engagement with the gear portion 232 of theupper portion 230 of the firing trigger 20, the upper portion 230 iscaused to rotate CCW, which causes the lower portion 228 to also rotateCCW.

When the knife 32 is fully deployed (i.e., at the end of the cuttingstroke), the front face 242 of the upper portion 230 trips the reversemotor sensor 130, which sends a signal to the motor 65 to reverserotational direction. This causes the main drive shaft assembly toreverse rotational direction to retract the knife 32. Reverse rotationof the main drive shaft assembly causes the gears 210-220 in the gearbox assembly 200 to reverse direction, which causes the upper portion230 of the firing trigger 20 to rotate CW, which causes the lowerportion 228 of the firing trigger 20 to rotate CW until the front face242 of the upper portion 230 trips or actuates the stop motor sensor 142when the knife 32 is fully retracted, which causes the motor 65 to stop.In that way, the user experiences feedback regarding deployment of theend effector 12 by way of the user's grip on the firing trigger 20.Thus, when the user retracts the firing trigger 20, the operator willexperience a resistance related to the deployment of the end effector 12and, in particular, to the loading force experienced by the knife 32.Similarly, when the operator releases the firing trigger 20 after thecutting/stapling operation so that it can return to its originalposition, the user will experience a CW rotation force from the firingtrigger 20 that is generally proportional to the reverse speed of themotor 65.

It should also be noted that in this embodiment the user can apply force(either in lieu of or in addition to the force from the motor 65) toactuate the main drive shaft assembly (and hence the cutting/staplingoperation of the end effector 12) through retracting the firing trigger20. That is, retracting the firing trigger 20 causes the gear portion232 of the upper portion 230 to rotate CCW, which causes the gears ofthe gear box assembly 200 to rotate, thereby causing the pinion gear 124to rotate, which causes the main drive shaft assembly to rotate.

The above-described embodiments employed power-assist user feedbacksystems, with or without adaptive control (e.g., using a sensor 110,130, and 142 outside of the closed loop system of the motor, gear drivetrain, and end effector) for a two-stroke, motorized surgical cuttingand fastening instrument. That is, force applied by the user inretracting the firing trigger 20 may be added to the force applied bythe motor 65 by virtue of the firing trigger 20 being geared into(either directly or indirectly) the gear drive train between the motor65 and the main drive shaft 48. In other embodiments of the presentinvention, the user may be provided with tactile feedback regarding theposition of the knife 32 in the end effector 12, but without having thefiring trigger 20 geared into the gear drive train. FIGS. 37-40illustrate a motorized surgical cutting and fastening instrument 10 withsuch a tactile position feedback system.

In the illustrated embodiment of FIGS. 37-40, the firing trigger 20 mayhave a lower portion 228 and an upper portion 230, similar to theinstrument 10 shown in FIGS. 32-36. Unlike the embodiment of FIGS.32-36, however, the upper portion 230 does not have a gear portion thatmates with part of the gear drive train. Instead, the instrument 10includes a second motor 265 with a threaded rod 266 threaded therein.The threaded rod 266 reciprocates longitudinally in and out of the motor265 as the motor 265 rotates, depending on the direction of rotation.The instrument 10 also includes an encoder 268 that is responsive to therotations of the main drive shaft 48 for translating the incrementalangular motion of the main drive shaft 48 (or other component of themain drive assembly) into a corresponding series of digital signals, forexample. In the illustrated embodiment, the pinion gear 124 includes aproximate drive shaft 270 that connects to the encoder 268.

The instrument 10 also includes a control circuit (not shown), which maybe implemented using a microcontroller or some other type of integratedcircuit, that receives the digital signals from the encoder 268. Basedon the signals from the encoder 268, the control circuit may calculatethe stage of deployment of the knife 32 in the end effector 12. That is,the control circuit can calculate if the knife 32 is fully deployed,fully retracted, or at an intermittent stage. Based on the calculationof the stage of deployment of the end effector 12, the control circuitmay send a signal to the second motor 265 to control its rotation tothereby control the reciprocating movement of the threaded rod 266.

In operation, as shown in FIG. 37, when the closure trigger 18 is notlocked into the clamped position, the firing trigger 20 rotated awayfrom the pistol grip portion 26 of the handle 6 such that the front face242 of the upper portion 230 of the firing trigger 20 is not in contactwith the proximate end of the threaded rod 266. When the operatorretracts the closure trigger 18 and locks it in the clamped position,the firing trigger 20 rotates slightly towards the closure trigger 18 sothat the operator can grasp the firing trigger 20, as shown in FIG. 38.In this position, the front face 242 of the upper portion 230 contactsthe proximate end of the threaded rod 266.

As the user then retracts the firing trigger 20, after an initialrotational amount (e.g., 5 degrees of rotation) the run motor sensor 110may be activated such that, as explained above, the sensor 110 sends asignal to the motor 65 to cause it to rotate at a forward speedproportional to the amount of retraction force applied by the operatorto the firing trigger 20. Forward rotation of the motor 65 causes themain drive shaft 48 to rotate via the gear drive train, which causes theknife 32 and sled 33 to travel down the channel 22 and sever tissueclamped in the end effector 12. The control circuit receives the outputsignals from the encoder 268 regarding the incremental rotations of themain drive shaft assembly and sends a signal to the second motor 265 tocause the second motor 265 to rotate, which causes the threaded rod 266to retract into the motor 265. This allows the upper portion 230 of thefiring trigger 20 to rotate CCW, which allows the lower portion 228 ofthe firing trigger to also rotate CCW. In that way, because thereciprocating movement of the threaded rod 266 is related to therotations of the main drive shaft assembly, the operator of theinstrument 10, by way of his/her grip on the firing trigger 20,experiences tactile feedback as to the position of the end effector 12.The retraction force applied by the operator, however, does not directlyaffect the drive of the main drive shaft assembly because the firingtrigger 20 is not geared into the gear drive train in this embodiment.

By virtue of tracking the incremental rotations of the main drive shaftassembly via the output signals from the encoder 268, the controlcircuit can calculate when the knife 32 is fully deployed (i.e., fullyextended). At this point, the control circuit may send a signal to themotor 65 to reverse direction to cause retraction of the knife 32. Thereverse direction of the motor 65 causes the rotation of the main driveshaft assembly to reverse direction, which is also detected by theencoder 268. Based on the reverse rotation detected by the encoder 268,the control circuit sends a signal to the second motor 265 to cause itto reverse rotational direction such that the threaded rod 266 starts toextend longitudinally from the motor 265. This motion forces the upperportion 230 of the firing trigger 20 to rotate CW, which causes thelower portion 228 to rotate CW. In that way, the operator may experiencea CW force from the firing trigger 20, which provides feedback to theoperator as to the retraction position of the knife 32 in the endeffector 12. The control circuit can determine when the knife 32 isfully retracted. At this point, the control circuit may send a signal tothe motor 65 to stop rotation.

According to other embodiments, rather than having the control circuitdetermine the position of the knife 32, reverse motor and stop motorsensors may be used, as described above. In addition, rather than usinga proportional sensor 110 to control the rotation of the motor 65, anon/off switch or sensor can be used. In such an embodiment, the operatorwould not be able to control the rate of rotation of the motor 65.Rather, it would rotate at a preprogrammed rate.

The various embodiments of the present invention have been describedabove in connection with cutting-type surgical instruments. It should benoted, however, that in other embodiments, the inventive surgicalinstrument disclosed herein need not be a cutting-type surgicalinstrument. For example, it could be a non-cutting endoscopicinstrument, a grasper, a stapler, a clip applier, an access device, adrug/gene therapy delivery device, an energy device using ultrasound,RF, laser, etc.

Although the present invention has been described herein in connectionwith certain disclosed embodiments, many modifications and variations tothose embodiments may be implemented. For example, different types ofend effectors may be employed. Also, where materials are disclosed forcertain components, other materials may be used. The foregoingdescription and following claims are intended to cover all suchmodification and variations.

Any patent, publication, or other disclosure material, in whole or inpart, that is said to be incorporated by reference herein isincorporated herein only to the extent that the incorporated materialsdoes not conflict with existing definitions, statements, or otherdisclosure material set forth in this disclosure. As such, and to theextent necessary, the disclosure as explicitly set forth hereinsupersedes any conflicting material incorporated herein by reference.Any material, or portion thereof, that is said to be incorporated byreference herein, but which conflicts with existing definitions,statements, or other disclosure material set forth herein will only beincorporated to the extent that no conflict arises between thatincorporated material and the existing disclosure material.

1. A surgical cutting and stapling instrument comprising: an endeffector comprising: a channel; an anvil pivotally attached to thechannel; a moveable cutting instrument for cutting an object positionedbetween the anvil and the channel; and a staple cartridge configured forremovable receipt by the channel, wherein the staple cartridge comprisesa sled that is engaged by the cutting instrument during a cuttingstroke; a handle comprising: a pistol grip portion; a closure triggercomprising a first end and a second end opposite the first end, whereinthe first end of the closure trigger is pivotably attached to the handlesuch that the closure trigger is retractable toward the pistol gripportion, and wherein retraction of the closure trigger toward the pistolgrip portion causes the end effector to clamp the object positionedbetween the anvil and the channel; a firing trigger, separate from theclosure trigger, wherein retraction of the firing trigger toward thepistol grip portion enables operation of a motor for actuating thecutting instrument via a main drive shaft assembly; and a closuretrigger locking assembly for releasably connecting the second end of theclosure trigger to the pistol grip portion when the closure trigger isretracted; a first electronic circuit for enabling initiation of motoroperation based upon a position of the staple cartridge; and a secondelectronic circuit for preventing the closure trigger locking assemblyfrom disconnecting the second end of the closure trigger from the pistolgrip portion until movement of the cutting instrument stops.
 2. Thesurgical instrument of claim 1, wherein the second electronic circuitcomprises an electromechanical actuator.
 3. The surgical instrument ofclaim 1, wherein the first electronic circuit is further for enablinginitiation of motor operation based upon at least one of a position ofthe anvil, a position of the sled within the staple cartridge, and anaccumulated number of operations performed by the instrument.
 4. Thesurgical instrument of claim 3, wherein the first electronic circuitcomprises: a first switch configured to maintain a first switch statewhen the staple cartridge is in a position corresponding to the receiptthereof by the channel; a second switch configured to maintain a secondswitch state when the anvil is in a closed position with respect to thechannel; a third switch configured to maintain a third switch state whenthe sled is present in an unfired position within the staple cartridge;and a fourth switch configured to maintain a fourth switch state whenthe accumulated number of operations is less than a pre-determinednumber; wherein the first, second, third, and fourth switches areconnected such that the corresponding first, second, third, and fourthswitch states, when collectively maintained, enable initiation of motoroperation.
 5. The surgical instrument of claim 4, wherein at least oneof the first, second, third, and fourth switches is selected from: acontact-actuated switch and a non-contact actuated switch.
 6. Thesurgical instrument of claim 4, wherein the first switch comprises afirst switch contact and a second switch contact disposed within thechannel and electrically isolated therefrom, wherein the first andsecond switch contacts are positioned such that a portion of the staplecartridge, when in the position corresponding to the receipt thereof bythe channel, establishes a conductive path between the first and secondswitch contacts.
 7. The surgical instrument of claim 4, wherein thesecond switch is further configured to maintain the second switch stateas a result of a mechanical force applied thereto when the anvil is inthe closed position relative to the channel.
 8. The surgical instrumentof claim 4, wherein the second switch is further configured to maintainthe second switch state responsive to an electrical signal, wherein theelectrical signal is representative of a force exerted by the anvil whenthe anvil is in the closed position.
 9. The surgical instrument of claim, wherein the second switch is further configured to maintain the secondswitch state after the anvil has been in the closed position withrespect to the channel for a pre-determined period of time.
 10. Thesurgical instrument of claim 4, wherein the third switch is furtherconfigured to maintain the third switch state as a result of amechanical force applied thereto by the sled when present in the unfiredposition.
 11. The surgical instrument of claim 4, further comprising acounter in communication with the fourth switch, wherein the counter isconfigured to maintain a count representative of the accumulated numberof operations and to cause the fourth switch to maintain the fourthswitch state when the count is less than the pre-determined number. 12.The surgical instrument of claim 11, wherein the counter is furtherconfigured to maintain the count based on one of a mechanical input andan electronic input received thereby.
 13. The surgical instrument ofclaim 11, wherein the counter is in communication with a display forindicating one of the maintained count and a difference between thepre-determined number and the maintained count.
 14. The surgicalinstrument of claim 4, further comprising at least one indicatordisplaying a status of at least one of the first, second, third, andfourth switches.
 15. The surgical instrument of claim 4, wherein each ofthe first, second, and third switches is characterized by anormally-open switch configuration, and wherein the fourth switch ischaracterized by a normally-closed switch configuration.
 16. Thesurgical instrument of claim 15, wherein the first, second, third, andfourth switches are connected in series with one of the motor and amotor control circuit such that initiation of motor operation isprevented when any of the first, second, third, or fourth switch statesis not maintained.